The widespread uptake and use of emissive metal ion complexes for investigating cellular structure, composition and function, is evidence of the effectiveness and vast potential for this type of imaging probe. Metal ion complexes provide significant advantages over their organic fluorophore counterparts, including long emission lifetime, resistance to photobleaching and the capacity to readily modify their peripheral chemistry to target specific organelles, signalling pathways and individual molecules. This review will discuss recent progress in the development and use of metal ion complexes, specifically for studying metabolic diseases at the cellular level. Advanced metal ion complexes for organelle imaging and the detection of biorelevant species, to elaborate complexes for understanding cellular mechanisms and recent therapeutic applications will be reviewed. To align with the special issue, Coordination Chemistry Reviews: Coordination Chemistry in Australia, the work of Australian researchers actively engaged in this field is featured prominently, along with key developments from the global research community.